[acme@mica linux]$ perf stat ls > /dev/null

 Performance counter stats for 'ls':

           1.512532  task-clock-msecs         #      0.801 CPUs
                  2  context-switches         #      0.001 M/sec
                  0  CPU-migrations           #      0.000 M/sec
                241  page-faults              #      0.159 M/sec
          2,973,331  cycles                   #   1965.797 M/sec
          1,460,802  instructions             #      0.491 IPC
            314,642  branches                 #    208.023 M/sec
             18,475  branch-misses            #      5.872 %
      <not counted>  cache-references
      <not counted>  cache-misses

        0.001887676  seconds time elapsed

To get the previous behaviour just use --no-big-num:

[acme@mica linux]$ perf stat --no-big-num ls > /dev/null

 Performance counter stats for 'ls':

           1.468014  task-clock-msecs         #      0.795 CPUs
                  1  context-switches         #      0.001 M/sec
                  0  CPU-migrations           #      0.000 M/sec
                241  page-faults              #      0.164 M/sec
            2900254  cycles                   #   1975.631 M/sec
            1437991  instructions             #      0.496 IPC
             310905  branches                 #    211.786 M/sec
              17912  branch-misses            #      5.761 %
      <not counted>  cache-references
      <not counted>  cache-misses

        0.001845435  seconds time elapsed

[acme@mica linux]$
Suggested-by: Ingo Molnar <mingo@elte.hu>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Stephane Eranian <eranian@google.com>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>